The present invention is generally directed to a safety switch for disabling operation of a hand-carried appliance, e.g., a hair dryer, during detected periods of non-use, e.g., when the appliance is put down, when the appliance is held in a non-functional position, etc.
Since the introduction of the hand-held hair dryer many features have been added to expand the utility of the product and improve its function. Typically, hair dryers now have ground fault interrupters (GFIs) on their power plugs for safety and may have shut offs for when they overheat. Multiple speeds and heat settings are now included on most models and some have a special one-touch cold setting. Numerous attachments have been added such as diffusers and cones to focus the heat as well as to add volume. Also many dryers now come in decorator colors with retractable cords and wall mountings. For real aficionados, there are also quiet dryers and ionic dryers for quicker drying. All of these features have made drying one""s hair safer, easier, and more efficient.
However, for anyone who has ever used a hand-held hair dryer, the real problem is how to shift from preparing the hair for receiving the heat with only two hands. The usual scenario is to turn off the dryer and put it down. Then with one hand holding the brush, the other hand is used to wrap the intended section of hair around the brush in readiness to receive the heat. Once that is completed, while holding the brush in one hand, one must then pick up the dryer with the free hand and with that same hand that is used to hold the dryer to somehow move one""s fingers nimbly around the dryer to flip the power switch to again turn on the dryer. Once that section of hair is satisfactorily dry, the process begins again. For women with anything other than very short hair and especially those who are trying to use the dryer to straighten hair this is an arduous, often exhausting process. For older people, especially those with beginning or moderate forms of arthritis, it is almost impossible to navigate the use of a hair dryer in any effective way. If one puts the dryer down on the counter without turning it off first, it will, within seconds, begin to move around wildly, at best blowing items around on the counter and at worst, falling off the counter onto the floor. At many beauty salons, the stylist often holds the activated dryer under his/her arm pit which can result in the air blowing into the face of the adjoining client. The only product known to the inventors of the present invention to even partially address this problem comprises a hair dryer with a wall mounted bracket that contains a mechanical power switch that removes power from the hair dryer when the hair dryer is mechanically snapped into the bracket.
The present invention is directed to a safety switch apparatus for disabling operation of a hand-carried appliance, e.g., a hair dryer, during periods of nonuse such as when the appliance is put down on a prescribed surface or placed in a non-functional position such as when it is held under a user""s arm. In preferred embodiments, a sensor, e.g., a hall effect sensor, a magnetoresistive sensor, a reed switch, or the like is coupled to control circuitry within the appliance to remove power from portions of the device, e.g., its motor and/or heater, when the appliance is proximate to an externally-provided magnetic field preferably provided from a magnetic element typically contained within a pad placeable on a work surface, e.g., a counter top.
In accordance with a preferred embodiment suitable for use with a hair dryer wherein the hair dryer comprises a motor and a heater, a safety system comprises (1) a sensor for detecting presence of an externally-provided magnetic field, e.g., a hall effect sensor, a magnetoresistive sensor, and a reed switch or the like; and (2) control and switch circuitry for alternatively supplying or removing power to/from the motor and/or heater; wherein the sensor is coupled to the control circuitry and in response to a detected magnetic field, the control and switch circuitry removes power from the motor and/or heater.
In a significant aspect of a preferred embodiment, said control and switch circuitry supplies power to the motor and/or heater in response to the absence of a magnetic field. Additionally, preferred embodiments additionally remove power from the control circuitry after a magnetic field is detected for a prescribed period.
In a further aspect of a preferred embodiment, the externally-provided magnetic field is supplied from a planar member suitable for placement on a work surface. Typically, the planar member is a conventional xe2x80x9crefrigerator magnetxe2x80x9d and is preferably contained with a multilayer structure having soft and/or elastic outer layers similar to a conventional xe2x80x9cmouse padxe2x80x9d.
In a still further aspect of a preferred embodiment, the externally-provided magnetic field may alternatively be provided by a magnetic element built into a work surface or contained within a wearable piece of clothing.
In an alternative implementation of the present invention, the sensor may be a tuned circuit which is sensitive to the proximity of a metallic, e.g., ferrous, element and the metallic element is located in an externally-provided planar member, a work surface or within an article of clothing.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.